Some of the definitions used in 1960 differ from those used in 1950. These changes were made after consultation with users of census data in order to improve the statistics, even though it was recognized that comparability would be affected. The definitions and explanations should be interpreted in the context of the 1960 Censuses, in which data were collected by a combination of self-enumeration, direct interview, and observation, by the enumerator.

The definitions below are consistent with the instructions given to the enumerator. As in all surveys, there were some failures to execute the instructions exactly. Through the forms distributed to households, the respondents were given explanations of some of the questions more uniformly than would have been given in direct interviews. Nevertheless, it was not feasible to give the full instructions to the respondents, and some erroneous replies have undoubtedly gone undetected.

More complete discussions of the definitions of population items are given in 1960 Census of Population, Volume I, Characteristics of the Population, Part 1, United States Summary, and in each of the State parts.

Nativity, Parentage, and Country of Origin

This report presents data on the nativity and parentage of the total population and the country of origin of the' foreign stock. These data were derived from answers to the questions on the Household Questionnaire shown in the next column.

This category comprises persons born in the United States, the Commonwealth of Puerto Rico, or a possession of the United States. Also included in this category is the small number of persons who, although they were born in a foreign country or at sea, have at least one native American parent. Persons whose place of birth was not reported are assumed to be native unless their census report contains contradictory information, such as an entry of a language spoken prior to coming to the United States.

The native population is further classified on the basis of the country of origin of parents into the two groups, native of native parentage and native of foreign or mixed parentage, described below.
Information on place of birth of the native population is published in the 1960 report PC(2)-2A, State of Birth.

This category comprises all persons not classified as native. Therefore, this group includes persons who reported a foreign country as their place of birth (with the exception stated above) and those persons with place of birth not reported who answered the question on language spoken prior to coming to the United States.

This group consists of native persons, one or both of whose parents are foreign born. The rules for determining the nativity of parents are substantially the same as those for determining the nativity of the persons enumerated. A limited amount of data is presented separately for the three groups comprising this category; namely, native of foreign parentage (that is, native with both father and mother foreign born), native of mixed parentage-father (but not mother) foreign born, and native of mixed parentage-mother (but not father) foreign born.

The foreign-born population is combined with the native population of foreign or mixed parentage in a single category termed the "foreign stock." This category comprises all first and second generation Americans. Third and subsequent generations are described as "native of native parentage." Age data for the total foreign stock are presented in this report in table 14; all other data for the foreign stock are classified by nativity.

In this report, persons of foreign stock are classified according to their country of origin, with separate distributions shown for the country of birth of the foreign born and the parents' country of birth for the native of foreign or mixed parentage. Native persons of foreign parentage whose parents were born in different countries are classified according to the country of birth of the father.

The question on place of birth and parents' birthplace specified that country of birth be reported according to international boundaries as recognized by the United States at the time of the census. (See excerpt from questionnaire above.) Because of the many changes in boundaries that have occurred over the past hundred years in the areas from which the major segment of the foreign stock _have emigrated, it is reasonable to expect that these instructions may not have been followed in all instances. Some misreporting of place of birth by persons ignorant of boundary changes, as well as by persons of illegal immigration status, most likely exists. Although no specific evidence can be cited for 1960, on the basis of data from the Post Enumeration Survey for 1950, it was estimated that the same country of- birth was obtained in the census and the survey for approximately 90 percent of the foreign-born persons properly included in the 1950 Census.

Table B. Median Age of the Foreign Born, for the United States, 1960, and of the Foreign-Born White, for Conterminous Untied States, 1950 and 1940, By Selected Country of Origin

In this century, nativity and parentage data have been available for the total population from the 1900 and 1960 Censuses only; for intervening censuses, tabulations were made for only the white population. In order to permit historical comparisons, a number of tables in this report are shown for both the total and the white population.

Historically most of the immigrants to the United States were from European countries, and, therefore, only a small proportion of the immigrants were non-white. With the decline in immigration this situation has been changing, as is reflected in the increasing proportion of nonwhites in the foreign-born population (table C).

Table C. Foreign-Born Population, Total and Nonwhite, For Conterminous United States: 1900 To 1960

Census year

Total

Nonwhite

Number

Percent

1960

9,661,028

381,709

4.0

1950

10,347,395

251,980

2.4

1940

11,594,896

175,758

1.5

1930

14,204,149

220,744

1.6

1920

13,920,692

207,938

1.5

1910

13,515,886

170,341

1.3

1900

10,341,276

127,459

1.2

Besides the inclusion of the foreign nonwhite stock, there are other inconsistencies between 1960 and earlier censuses. The general method of processing the returns for country of origin was the same for the 1950 and 1960 Censuses; however, a slight variation was introduced in the handling of entries of Austria-Hungary. In 1950, the technique of assigning a specific country for entries of Austria-Hungary depended on the surname. In 1960, a question on mother tongue was asked of all foreign-born persons and the allocation to a specific country was made on the basis of the language reported. For example, persons reporting Rumanian were classified as born in Rumania. For blanks on mother tongue, a system was devised to allocate the entries of Austria-Hungary in the coding operation on the basis of the distribution of nationalities of migrants from the Austro-Hungarian Empire as reported in the 1920 Census report, Volume II, Population. It appears that, as a result of these revisions in the coding procedures, the apparent understatement in the number of persons of Yugoslavian origin, which was evident in the data for 1950, does not exist in the published 1960 statistics. The change in the method of processing entries of Austria-Hungary combined with the improvements resulting from self- enumeration may have been responsible for the better coverage. (For additional information on these data see the text in Volume I, Characteristics of the Population, Part 1, United States Summary.)

The distinction between Canada-French and Canada- Other was not maintained in the collection and publication of 1960 data on country of origin. Data for 1960 for persons of Canadian origin are comparable with the sum of the categories Canada-Other and Canada-French from earlier censuses.

Prior to 1950, questions on citizenship and mother tongue were used, when feasible, to assign entries on nativity and country of origin where these entries were omitted or uncodable. In the 1950 Census the question on mother tongue was excluded; in 1960, this question was asked of the foreign born, but citizenship was not asked. Data for 1960 on mother tongue are to be presented in the forthcoming report PC(2)-1E, Mother Tongue.

The classification by country of origin appears to be consistent with the expected values based on an examination of past censuses. In countries where the same boundaries have been maintained over a long period of time, the classification by country of origin appears to be reasonable.

The data seem to indicate that a completely accurate count of the foreign stock from areas in which there had been considerable boundary changes after World War I may not have been achieved. An example of such a problem is found in the reporting of Austria- Hungary as place of birth. A discussion of the technique designed to handle such entries is given above in the section on "Comparability of the data."

Changes from 1940 to 1950 and from 1950 to 1960 in the foreign stock from Ireland (Eire), Northern Ireland, and, consequently, the United Kingdom seem to reflect errors in reporting rather than actual changes in the numbers in each category. Because of the omission from the schedule of any instruction to distinguish Northern Ireland and Ireland (Eire) in 1950, the number of persons of foreign stock from Northern Ireland was apparently underreported to a considerable degree in that census and that from Ireland, correspondingly overreported. The reinstated special caution relating to this point on the 1960 questionnaire resulted in a very different and probably more correct distribution between the two countries. The foreign born from Northern Ireland increased by 340 percent and those from Ireland decreased by 33 percent between 1950 and 1960. Similar changes occurred for native persons of Irish parentage. The decline in the foreign stock from the United Kingdom between 1950 and 1960 undoubtedly would have been greater had it not been affected by the spurious increase in the figure for Northern Ireland.

The median is presented in connection with the data on age and years of school completed. It is the value which divides the distribution into two equal parts, one-half the cases falling below this value and one-half the cases exceeding this value. Median age for 1960 was computed on the basis of the 10-year age groups shown in .this report; for earlier years, medians are based on 5-year age groups published in previous reports.

For 1960, the term "United States" when used without qualifications refers to the 50 States and the District of Columbia. In some tables, to preserve historical comparability, 1960 totals are shown for the 48 States and the District of Columbia, excluding Alaska and Hawaii. This area is designated "conterminous United States." For earlier censuses, this term refers to the expanding area of the United States (regardless of status as a State or territory) within the area of the 48 States and the District of Columbia.

Metropolitan-nonmetropolitan residence refers to residence inside or outside standard metropolitan statistical areas (SMSA's). Except in New England, an SMSA is a county or group of contiguous counties which contains at least one city of 50,000 inhabitants or more, or "twin cities" with a combined population of at least 50,000. In addition to the county, or counties, containing such a city or cities, contiguous counties are included in an SMSA if, according to certain criteria, they are essentially metropolitan in character and are socially and economically integrated with the central city. In New England, SMSA's consist of towns and cities, rather than counties.

The term "color" refers to the division of population into two groups, white and nonwhite. The color group designated as "nonwhite" consists of such races as the Negro, American Indian, Japanese, Chinese, Filipino, Korean, Asian, Indian, and Malayan races. Persons of Mexican birth or ancestry who are not definitely of Indian or other nonwhite race are classified as white.

The data on years of school completed were derived from the answers to the two questions: (a) "What is the highest grade (or year) of regular school he has ever attended?" and (b) "Did he finish this grade (or year)?" Enumerators were instructed to obtain the approximate equivalent grade in the American school system for persons whose highest grade of attendance was in a foreign school system, whose highest level of attendance was in an ungraded school, whose highest level of schooling was measured by "readers," or whose training by a tutor was regarded as qualifying under the "regular" school definition. Persons were to answer "No" to the second question if they were attending school, had completed only part of a grade before they dropped out, or failed to pass the last grade attended.

The number in each category of highest grade of school completed represents the combination of (a) persons who reported that they had attended the indicated grade and finished it, and (b) those who had attended the next higher grade but had not finished it.

The questions on educational attainment applied only to progress in "regular" schools. Regular schooling is that which may advance a person toward an elementary school certificate or high school diploma, or a college, university, or professional degree. Schooling that was not obtained in a regular school and schooling from a tutor or through correspondence courses were counted only if the credits obtained were regarded as transferable to a school in the regular school system. Schooling which is generally regarded as not regular includes that which is given in nursery schools; in specialized vocational, trade, or business schools; in on-the-job training; and through correspondence courses.

Elementary school, as defined here, includes grades 1 to 8, and high school includes grades 9 to 12. College includes junior or community colleges, regular 4-year colleges, and graduate or professional schools. The category "less than 5 years" includes persons reporting "none" for years of school completed.

This classification refers to the marital status of the person at the time of enumeration. Persons classified as "married" comprise, therefore, both those who have been married only once and those who remarried after having been widowed or divorced. Moreover, persons shown as married include those who are either legally separated or otherwise absent from their spouse because of marital discord. The enumerators were instructed to report persons in common-law marriages as married and persons whose only marriage had been annulled as single.

The number of married men may be different from the number of married women for an area because of the absence of husbands or wives from the country, because the husband and wife have different places of residence, because of the methods used to inflate the sample data, or for other reasons.

The data on employment status relate to the calendar week prior to the date on which the respondents filled their Household Questionnaires or were interviewed by enumerators. This week is not the same for all respondents because not all persons were enumerated during the same week.

Employed persons comprise all civilians years old and over who were either (a) "at work"-those who did any work for pay or profit, or worked without pay for 15 hours or more on a family farm or in a family business; or (b) were "with a job but not at work"-those who did not work and were not looking for work but had a job or business from which they were temporarily absent because of bad weather, industrial dispute, vacation, illness, or other personal reasons.

The data on occupation in this report are for employed persons and refer to the job held during the week for which employment status was-reported. For persons employed at two or more jobs, the data refer to the job at which the person worked the greatest number of hours. The occupation statistics presented here are based on the detailed systems developed for the 1960 Census; see 1960 Census of Population, Classified Index of Occupations and Industries, U.S. Government Printing Office, Washington, D.C., 1960.

White-collar workers include the following major occupation groups: Professional, technical, and kindred workers; managers, officials, and proprietors, except farm; clerical and kindred workers; and sales workers.